About 23 miles southeast of Las Vegas, on the Arizona-Nevada border, sits one of the highest concrete dams in the world - the Hoover Dam. Security for the $385 million structure - which cost $175 million to build in 1936 - is no small task. A lot is at stake. If the Hoover Dam were to be shut down, about 30 million people in the Southwest would be out of water, says Mike Eaker, manager of communications for the Bureau of Reclamation, which designed and supervises the dam. Located on the Colorado River, the Hoover Dam created the 115-mile Lake Mead, one of the world's largest man-made lakes. Named for President Herbert Hoover, who spearheaded the flood-control measure to create jobs during the Depression, the dam today plays a powerful role in the Southwest region's economy, supplying much of the electricity consumed by Arizona, Nevada and southern California. "This is considered the premier power hydraulic facility in the United States," Eaker says. Eaker was handed the task of finding a suitable security system for the dam in 1993 after a federal security assessment determined that the dam and its properties were "vulnerable." At that time, only a private police force was employed; there was no remote monitoring on the site. Assessment of the dam mandated a minimal surveillance system. Almost as wide as it is deep, the dam is 726 feet tall and 1,244 feet long. Elevators, which can descend the equivalent of 44 stories into the dam, still cannot reach the 660-foot-thick base, rooted 100 feet below the river bed. The dam contains enough concrete - 4.5 million cubic yards - to pave a two-lane highway from New York to San Francisco. In his search for security ideas, Eaker cruised the Las Vegas "Strip" of gambling casinos, where surveillance systems abound, and toured Nelles Air Force Base and other power plants near Las Vegas. Eaker then hired a local security systems dealer/installer/contractor, Global Surveillance Associates (GSA), to install a surveillance system consisting of a few fixed cameras and housings in the parking garage, the visitor's center and the warehouse. Since that time, the "minimal surveillance system" required to monitor the Hoover Dam property has grown into a multi-purpose security system. And the system, which uses equipment by Philips Communication and Security Systems, is continuing to grow, with more cameras planned for the parking garage, Eaker says. Originally, all cameras were linked to the Philips TC8500 Allegiant microprocessor-based switcher/controller with viewing on Philips monitors.

>From that initial 8- or 10-camera system, the dam's current security system has expanded to 32 cameras, including fixed and AutoDomes, two time-lapse recorders and additional monitors. The surveillance system has been instrumental in investigations involving muggings, break-ins and other criminal mischief at the dam, Eaker says. Fixed cameras in the parking lot monitor activity for public safety, and AutoDomes overlooking the dam wall record the water level. Cameras in the exhibit building, which houses a model of the river basin, pan the area for intruders. "The only people who are here on the weekends are tourists during the daytime hours," Eaker says. "About a half dozen power plant operators are here at night. One person is dedicated to watching the monitors. We have our own security forces here - the control room operators. At night, the operators continuously pan the entire area." The main fiber-optic cable for the cameras runs from the eighth floor up the incline tunnel, carved into the canyon wall under the visitor's center, to the control room. The tunnel has a 37-degree angle that travels 1,800 feet down into the power plant. Video is carried to the control room where an operator watches four 14-inch color monitors. Video is recorded and played back through the Philips TC8298B Series Color Allplex 16-channel video multiplexer. Time-lapse VCRs record the video. Two VCRs are used; half of the cameras are recorded on the first VCR and the others on the second. The video switcher/controller has full matrix switching capabilities and can be programmed to display video from any camera on any monitor, either manually or via independent, automatic switching sequences. On-site receiver/drivers permit operator control of pan/tilt/zoom, multiple pre-positions, four auxiliaries, auto-pan and random scan.